Emergency Brake does nothing

sgiangregorio · May 1, 2005

(I did a search, couldn't really find anything.)

I assume my e-brake cable is frozen or something...the other day, I had the brake on, but drove for a few feet before I recalled it being on. That led me to question why it wasn't pulling more on the truck, so I played around with it, and basically it did very little.

The regular brakes are fine, so is this a frozen cable? There's almost no resistance when pressing the e-brake pedal to the floor too.

Thanks for the help.

Stocklook · May 1, 2005

Same thing here But have not tryed to drive with it on, The e-brake pads are in the center of the rear disc, it is a drum type brake ??? But it seems to work, and the pedal has little to no pressure or effort to apply the brake

My .02 from what I was told. maybe someone else knows this better and will chime in

sgiangregorio · May 1, 2005

Disc brakes. Same pads are used, I believe, as normal braking. And when the brake's engaged, it will hardly, if at all, hold the vehicle from moving.

I trailer a boat, and rely on the e-brake when at the ramp, as well as chocks. Now knowing that the brake is doing nothing isn't comforting...

Thanks for the reply.

Indy · May 1, 2005

Disc brakes. Same pads are used, I believe, as normal braking. And when the brake's engaged, it will hardly, if at all, hold the vehicle from moving.

I trailer a boat, and rely on the e-brake when at the ramp, as well as chocks. Now knowing that the brake is doing nothing isn't comforting...

Thanks for the reply.

<{POST_SNAPBACK}>

The emergency brake is a drum brake set up seperate from the disc brake. The rear disc has a drum built in to the back of it. They can be adjusted in 2 ways. There's an adjuster on the back of the drum brake assembly and there is a cable adjuster about halfway back on the drivers side where the cable goes from 1 into left and right. 12mm nut I believe.

sgiangregorio · May 2, 2005

I stand corrected. That's interesting, I didn't know that. I'll have to look into adjusting then, thanks for the info.

Is it usually a pain, should I just have the dealer do it? I can imagine the nuts being all rusted out.

Indy · May 2, 2005

I stand corrected. That's interesting, I didn't know that. I'll have to look into adjusting then, thanks for the info.

Is it usually a pain, should I just have the dealer do it? I can imagine the nuts being all rusted out.

<{POST_SNAPBACK}>

The adjuster on the cable is a piece of cake to play with however the adjuster on the brake itself is hard to get to and can be tricky and they will break off quite easily if badly rusted.

dougmac · May 2, 2005

(I did a search, couldn't really find anything.)

I assume my e-brake cable is frozen or something...the other day, I had the brake on, but drove for a few feet before I recalled it being on. That led me to question why it wasn't pulling more on the truck, so I played around with it, and basically it did very little.

The regular brakes are fine, so is this a frozen cable? There's almost no resistance when pressing the e-brake pedal to the floor too.

Thanks for the help.

<{POST_SNAPBACK}>

This should help........

I have had to adjust mine twice since it was new. It now has 75,000 miles on it.

When it is in adjustment it will come up firm before it goes to the floor. When it is in need of an adjustment, it will go to the floor with very little effort and you can drive through it easily. When it is in adjustment it holds well.

Today I rotated the tires and adjusted the parking brake. I took photos so you can see how it is done. NOTE: this is the procedure for a 1500.

Block the wheels, put her on jack stands, release the parking brake and remove the rear wheels.

Remove the bolts that hold the caliper bracket to the dust shield. They are VERY TIGHT and come out HARD so you will want to have a GOOD quality, six point, ½” drive 18mm socket and a flex bar or a long ratchet.

Next slide the rotor/drum assembly off of the axle. Inspect the lining to make sure it is not worn.

Turn the adjuster to expand the lining. (the yellow arrow points to it) Expand the shoes so they are tight enough that you have to work to get the rotor/drum back on over the lining. If the rotor/drum slips on easily, they are not tight enough. Ensure that you can rotate the rotor/drum when it is back on. A light drag is OK.

Put the caliper and bracket back on. The bolts are patch bolts so ideally they should be replaced with new ones. I just put medium strength blue thread locker on the threads. DO NOT use the red super high strength thread locker unless you can insure that you will never have to remove them again. Torque the caliper bracket to dust shield bolts to 148 ft lbs.

Polish the wheel while you have it off. Then install and torque the wheel to 140 ft lbs. Your parking brake should feel firm and hold good.

Good Luck,

Doug

mmmikkke · May 2, 2005

...Polish the wheel while you have it off...

<{POST_SNAPBACK}>

Ahh, yes. Very important.

An often skipped step. And the polishing comes out much better when there no lug nuts to get in your way.

Nice post.

J-rod · May 2, 2005

Good stuff! I noticed just last week that mine holds so well you can't even tell it's enganged with the truck in gear and idling!

Anyway, I vote Doug's instructions get moved to the Tech > Maintenance section.

Thanks again for the info Doug!

Markeaux · May 3, 2005

Just to add: officially it's not an emergency brake, but rather a parking brake ... and it is normal for it to go all the way to the floor, it's called something like EZadjust, supposed to do that, and it (supposedly) adjusts itself; but, of course it's also supposed to hold the vehicle which mine always has even with it going all the way to floor ... but yes, many have adjusted it themselves or made mods to make it so you can feel tension part-way ... If you do some searching on this forum there will be lots of info, including about the TSB for the updated clip assembly that can keep the p-brake from always riding on the inside of its drum ruining the hub.

walbern1 · May 4, 2005

There was a problem with these on some years, a clip that normally holds the shoe in place doesn't work properly and the shoe rides out against the drum and causes premature wear. Check with your dealer and make sure you have the updated clip. Here is the TSB text from Alldata:

Bulletin No.: 02-05-26-002A

Date: February, 2003

TECHNICAL

Subject:

Scraping Noise From Rear Of Vehicle

(Replace Parking Brake Shoe Kit and Clean Drum In Hat Rotor)

Models:

2002-2003 Cadillac Escalade, Escalade EXT

1999-2003 Chevrolet Silverado 1500 Series Pickups

2000-2003 Chevrolet Suburban, Tahoe 1500 Series Models

2002-2003 Chevrolet Avalanche 1500 Series Models

1999-2003 GMC Sierra 1500 Series Pickups

2000-2003 GMC Yukon, Yukon XL 1500 Series Models

This bulletin is being revised to add Suburban and Yukon XL models. Please discard Corporate Bulletin Number 02-05-26-002 (Section 05 - Brakes).

Condition

Some customers may comment on a scraping noise from the rear of the vehicle while driving. The noise may be intermittent.

Cause

Condition may due to the parking brake shoe contacting the drum in hat rotor without the parking brake being applied, causing premature wear on the shoe lining.

Correction

Replace the parking brake shoe and install a new designed spring clip retainer. Follow the service procedure below to correct this condition.

1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in the General Information sub-section of the Service Information (SI Document ID # 639546).

2. Remove the tire and the wheel. Refer to Tire and Wheel Removal and Installation in the Tires and Wheels sub-section of the Service Information (SI Document ID # 656965).

3. Relieve the tension on the park brake cables by loosening the nut at the equalizer.

4. Mark the relationship of the rotor to the hub.

5. Remove the brake caliper bracket mounting bolts.

Notice : Support the brake caliper with heavy mechanic's wire, or equivalent, whenever it is separated from it's mount and the hydraulic flexible brake hose is still connected. Failure to support the caliper in this manner will cause the flexible brake hose to bear the weight of the caliper, which may cause damage to the brake hose and in turn may cause a brake fluid leak.

6. Remove the brake caliper and brake caliper bracket as an assembly and support with heavy mechanic's wire or equivalent. DO NOT disconnect the hydraulic brake flexible hose from the caliper.

7. Remove the rotor retaining push nuts from the wheel studs (if applicable).

Notice DO NOT use a hammer to remove the rotor from the hub; it may cause damage to the rotor.

Important : The rotor may not be easily removed from the hub due to a rust build up on the outside edge of the drum and hat portion of the rotor.

8. Remove the rotor from the hub. If the rotor cannot be removed from the hub by pulling on the rotor, use J 46277 rotor removal tool.

Notice : Place J 46277 between the rotor surfaces in the vent section of the rotor. DO NOT place J 46277 on the back side of the rotor surface, it may damage the rotor surface.

9. Using removal tool J 46277 on slide hammer J 6125B, remove the rotor by placing removal tool J 46277 in the vent section of the rotor at the twelve, three, six and nine o'clock positions, not necessarily in that order.

10. Clean the rust ridge from the drum portion of the rotor using a grinding stone and rotor resurfacing kit J 41013.

11. Remove the spring clip bolt (3) and retainer (2) and discard.

Important : Minimum thickness of the parking brake shoe lining in any given spot is 1.5 mm (0.06 in).

12. Measure the parking brake shoe thickness in multiple spots. Replace the parking brake shoe if the thickness is less than 1.5 mm (0.06 in). Continue with Step 14.

13. If the parking brake shoe lining is greater than 1.5 mm (0.06 in), continue with Step 19.

14. Rotate the parking brake shoe (1) out from the bottom and pull it out of the adjuster. Discard the shoe.

15. Remove the park brake shoe assembly from the vehicle by placing one of the open ends of the shoe over the axle flange and rotate the shoe until it has cleared the flange.

16. Turn the adjustment screw (1) to the fully home position in the notched adjustment nut.

17. Install the new park brake shoe assembly (1) from the parking brake shoe kit, P/N 88982875, to the vehicle by placing one of the open ends of the shoe over the axle flange and rotating the shoe until it is behind the flange.

18. Slide the shoe into the adjuster and position the shoe to the backing plate. Install the retaining spring clip (2) and bolt (3) from the parking brake shoe kit, P/N 88982875. If using parking brake service kit 88982875, SKIP Step 19.

19. Replace the retaining spring clip (2) and bolt (3) from the parking brake retaining spring clip kit, P/N 88982879.

Tighten :Tighten the bolt (3) to 5 N.M (44 lb in).

20. Set the J 21177-A so that it contacts the inside diameter of the rotor.

21. Position the J 21177-A over the shoe and the lining at the widest point.

Important : The parking brake adjustment screw threads should not exceed 5 mm (0.2 in) of exposed thread.

The clearance between the park brake shoe and the rotor is 0.6604 mm (0.026 in).

22. The parking brake adjustment screw threads should not exceed 5 mm (0.2 inch) of exposed thread.

Notice : Whenever the brake rotor has been separated from the wheel bearing flange, clean any rust or foreign material from the mating surface of the rotor and flange with the J 42450 hub cleaning kit. Failure to do this may result in increased lateral runout of the rotor and brake pulsation.

23. Use the J 42450-A to clean all rust and contaminants from the mating surface of the hub flange.

24. Use the J 41013 to clean all rust and contaminants from the inside diameter of the hat section of the brake rotor to prevent any foreign material from getting between the brake rotor and the hub flange.

25. Align the mark on the rotor with the mark on the hub and install the rotor by slowly turning the rotor while pushing the rotor towards the axle.

26. Install the caliper and the bracket as an assembly to the vehicle.

27. Perform the following procedure before installing the caliper bracket mounting bolts.

Remove all traces of the original adhesive.

Clean the threads of the bolt with brake parts cleaner, P/N 12346139 (Canadian P/N 10953463), and allow to dry.

Apply threadlocker, GM P/N 12345493 (Canadian P/N 10953488), or Red LOCTITE # 272, to the threads of the bolt.

Notice : Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

28. Install the caliper bracket mounting bolts.

Tighten : Tighten the brake caliper bracket mounting bolts to 175 N.m (129 lb ft).

29. Repeat this procedure on the other side of the vehicle.

30. Tighten the nut to the intermediate cable at the equalizer.

Tighten : Tighten the nut to 3.5 N.m (31 lb in).

31. Install the tire and wheel assembly. Refer to Tire and Wheel Removal and Installation in the Tires and Wheels sub-section of the Service Information (SI Document ID # 656965).

32. Lower the vehicle.

33. Verify that the self adjuster lock-out pin has been removed.

34. Fully apply and release the park brake pedal three times.